For those of you who might want to rediscover crocheting for yourself, here is a tip for getting started
To cast on stitches, pick up so-called air stitches. This means you take the beginning of your yarn and make a "fast" knot. In doing so, the end of the yarn is not pulled through loop, but only a section of the yarn, so that a loop is created. Through this loop you now pull with the help of the crochet hook a little from and the rest of Yarn, to make a loop again, etc. Each of these loops is a loop of air.
If you want to crochet firm stitches now, you must continue the air stitch row just crocheted as follows further
The last air stitch loop still on the crochet hook, now stitch through the next air stitch with the needle from above. You make a small loop, as before, but keep it as the second loop on the crochet hook. Then pull the Yarn through both loops - ready is the first fixed stitch. Crochet further, until you reach the end of the row.
There they take up an additional air stitches (simple loop) and crochet the row back again.